Rear bumper



FIG. 1 is a front perspective view of a rear bumper showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is an opposite side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

It will be understood that the broken lines shown in the drawings illustrate portions of the rear bumper that form no part of the claimed design. 

CLAIM The ornamental design for a rear bumper, as shown and described. 